When I did the install I squared them up and pressed them down with my thumbs then, used a socket  and give it some JKB love taps........be sure to put some clear rtv in the groove of the ring first.......

 

I emailed you an instruction sheet in case you don't have them any more.  Those bearing/seal driver tools work great.  Main key to getting them in there without damaging the paint on the wheel is to grind the paint off the edge of the hole before inserting the adapter.   That way the paint won't get chipped.  The new cap does cover the edge where paint is removed.

For those who have no clue what we are talking about, the adapter lets you put the hollow-back 06 or newer center caps on the older 01-04 Bullitt wheels.  If you narrow the wheels and bolt them on without a spacer, the original center cap (with solid back) cannot be used as it interferes with the bearing cap on the front hubs.  I offer an adapter kit to retrofit the newer caps to the older wheels.

I think the newer caps look alot better than the flush fit ones from 01-04.  The new ones are a "copy" of the 1965 styled steel wheel center cap.