What tools and sizes are needed for the three hole service on a 07 Road King

 

T-27 Torx for sure

Don't remember the socket sizes, but it's either 1/2 or 5/8 I believe

 

Like said T 27 torx, and make sure its not a T 25. A good set of allen wrenches, 3/8" socket set, 5/8comb wrenck, funnel, rags, a filter removal tool. you should be good to go

 

T-27 Torx for the derby cover screw and an Oil filter wrench (or strap wrench).
You may want to make holes in the filter to drain it before removing or
make a little funnel/tray to catch the drippings from the filter.
Also a socket or box end wrench (sorry I don't recall the size) for the drain plugs (if you have a torque wrench 14-21 ft lbs or 19-28.5 N.m).
A pan to catch the old fluids.
An allen wrench for the trans fill/dipstick (again I don't recall the size).
A funnel for pouring in new fluids.
A rag for cleaning up.

 

If you're going to be doing your own service you need to pick up a service manual. It's all in there.