The ‘tops’, by that I’m assuming you mean the rebound adjustment dials, they come off pretty easily. Lever CAREFULLY underneath evenly and they’re off. Under that is the plate that connects through to the mechanism, that can all stay on. A normal socket can get the cap bolts off. (21 / 22/ 23 / 24 mm? can’t remember at the minute).
There is a small drain hidden down the bottom of the fork, it is the 10mm head cap bolt. Don’t take out the philips head screw, there is a spring and ball under for the damping adjuster.
You will need to flush new oil through a few times as the passages are a bit convoluted in the anti dive circuitry.