Custom sub box for rear deck

Ok, I want to put a pair of probably 10" subs in the factory speaker location on the back deck of my 'lude. How would I go about enlarging the stock holes without causing a lot of damage, and get a good seal for the box? Also, I plan on leaving room for a pair of mid-ranges on the deck as well, so would it sound better to have them on the inside or the outside of the subs? What kind of box (or boxes) would yall recommend for this type of setup? I would like to keep as much trunk space intact as possible, and I don't want to block the access panel to the back seat. Any help would be great.

this is going to be very difficult because there are torsion bars under the package shelf that help hold the trunk lid up. I think you will find that the speakers that are back there are shallow mouint designs or manage to avoid the bars. Normally, you would put the mid/tweets on the outside of the subs. You might be better off getting a box that fits on the side of the trunk (behind the wheel well) ... and points to the other side.