I hope someone can tell me what tool will remove the drain plug in the bottom of the diff on my 05 3500.
Thanks

Should be just a ratchet plug. Use a ratchet and 2 inch extension and you should be in business.

Yep, just use 3/8" ratchet with a short extension.

At one time there was (maybe still is) a tool that had multiple square tips of different sizes on each end that fit about all common automotive plugs. Was called a dog-bone.