I converted my Super Stunt 40 and 60, both Stik type planes, to tail dragger. I posted pics of them somewhere in these forums a while back.

The mains are a no brainer. Add the ply backplate and bolt right on.

THe tailwheel is not difficult, but does require some planning depending on type of assembly you choose. I usually use the ho-hum tailwheel brackets that came on other ARFs, where I had replaced with better ones. ANyhow, not much reinforcement is required, but if you use one of those that mounts flat on the underside of the fuse (e.g. Sullivan), you may want to cut out a small patch of covering where you want to mount the tailwheel bracket, and glue on a piece of liteply. It will give the bracket a firmer base to mount on. Plus then you can use screws instead of needing nuts & bolts.