I've seen LT 40's that have been converted. It's not that hard.

Flyboys advice is good. You want the new landing gear to be ahead of the CG. In planes I've converted, I install light ply in the bottom of the fuse ahead of the wing, with triangle (or square) stock in the corners on top of the ply (adds stregth). The new gear bolts through the fuse and into the ply. Use blind nuts and nylon bolts if you can.

There are different oftions for a tail wheel and it's best if you can isolate the tail wheel control rod from the wheel itself (with springs or...) to reduce shocks to the servo, but not absolutely necessary.

Many tailwheels simply screw to the bottom of the fuse (you'll need to put a ply plate on the bottom of the fuse). Then there's an arm that must be bolted to the rudder. Not the best option perhaps, but they work.
Dennis-