Brison recommends replace the crank pin needle bearing whenever you have a prop strike the ground. Any idea how to replace these? Is this something I could do or should I have Brison replace them?

Give Gary or Harvey at Brison a call on Monday. They would be able to give you the straight up answer. It's possible that you may not need to replace it.

Did you break the prop? If not, I can't imagine that the force would be great enough to flatten the needles on the bearing.

If it was a wood prop, even breaking it probably did no harm. If it was impacted, too, then that's another story altogether.

I run a wooden prop. It hit the ground hard enough to stop the engine. The prop did not break. It is a new engine. I am reading this out of there instruction manual and am not sure what to do.

"What to do?"
I'd fire it up,fly the plane & not worry about it.I've got two Brison 3.2's,both have had a few "prop strikes" without any damage to the engines.Both run just fine.
They must have changed their instruction manual as mine DOES NOT say anything about replacing the bearings.

This is a statement right of there owers manual.
MAINTENANCE: Your new Brison engine will be, practically, maintenance free for several seasons. We do recommend a crank pin needle bearing replacement every time you have a prop strike or aerial crash. Maintenance of these bearings should be considered every 200 to 300 flying hours. Periodically check the sensor and ignition leads for chaffing.

I would just put another prop on and run it. I have the Brison 3.2 that had a prop strike that broke a pro zinger 22x8 sense than I had run 2 gal on it with no problems yet. 22x8 Menzs 7000 RPM.

Remove the spark plug and rotate the engine thorgh several revolutions by hand. If you don't feel any rough spots in the bearings as the crank makes full rotations, run it.

I have two 3.2's also. One of them was mounted in a G/P Pitts, making prop strikes almost a sure bet with the way the landing gear was set up. After several broken wooden props, I'm still continuously flying the engine almost a year after the fact with no ill effects.

Yep,it's on their web site.
Here is another "interesting" recommendation regarding fuel & oil:

"FUEL: Use high octane gasoline, leaded or unleaded with a good quality 2 cycle oil. You should use only synthetic oils such as Amsoil or Klotz. The recommended ratios are 64:1 to 100:1 with 64:1 being petroleum based oil and 80/100:1 being the synthetic. Our engines will run at 100:1 with GOOD synthetic oils. Never use more oil than necessary because it will stick the rings, causing the piston to melt, voiding your warranty."

I've run both petroleum based oil & synthetic at 40:1 & at 50:1 in my engines & have never had a "sticking ring."

64:1...? Well,I guess I just don't agree with that & I don't agree with the bearing replacement.

I just went through the same ordeal with my Brison 3.2 I bought it used through RCU Marketplace and when I received the "like new" engine, it looked like someone took a sledge hammer to the muffler. The tip of the sparkplug was also shaved flat indicating some sort of serious contact with terra firma. I called Brison and they told me to replace the needle bearing. A call to a nearby industrial bearing supply co. had it delivered overnight.(about $7.00 shipped). I took the engine apart and realized I couldn't or did not have the proper tool to properly remove the old bearing. I drove up to my car mechanic, who happened to be on his way to his " engine man" (rebuilds race car engines) and had my new bearing in my motor in 2 days. No charge for this and my engine purrs like a kitten. Was this necesarry? I don't know for sure but I feel better now that it's over with.

With a wood propeller, I would not worry about replacing anything.
Just start the engine and enjoy

EJB
I have lost an engine using to much oil. I was running a Brison engine on 40 to 1 mix. ring stuck and well the engine is in the garbage. The ring blew out and scared the piston and cylinder. It was real sad.