I presume "pressure dents" are shallow smooth dips, not hard, defined nicks. Remove the car body (usually 6 tabs under the frame). Place the body upside down thumb on a slightly flexible surface to support the entre roof (ex., high density foam, folded towel, etc.). Use your thumb to rub the inside of the dent continually pressure until it smooths the dent.
When removing the body, it's not necessary to completely straiten the tabs (they'll break with repeated bending), Bend them about 45 deg. or slightly more. Then tilt the body to release one side of tabs and repeat on the other side to remove the body. Use the "spring" of the tabs to release them instead of completely bending them. You can massage the body back on the frame the same way.
