If you don't have it, buy an alignment tool - you can get these with the driver attachment to drive in the new gimbal bearing. I also bought a gimbal bearing puller tool - mine was so tight it would have been miserable to pull with a slide hammer.
You may want a flexible shaft screwdriver to tighten the clamps on the main bellows.
If you're replacing your lower shift cable, you'll need the tool to remove the cable (it's basically an extra-deep well 9/16" socket).
Hopefully you bought a genuine Mercruiser / Quicksilver bellows kit. Aftermarket kits are made of an inferior rubber and likely won't last as long.