Yes matey.
Remove Clutch hub centre, if you're going to drill extra oil feed holes (i would)
Drilling swarf in a motor is not good.
No need to remove outer basket, drilling mod only need to be done to inner hub.
I mark position of steel plates on outer basket, with a Sharpie marker, crack loose hub nut with ya new clutch holding tool, leave nut on, remove all plates & transfer hole centre positions to inner hub from outer basket before you remove it, now you have the spacings of the steels, up to you then how you space the holes radially, but doing it this way ensures you get oil feed holes in between the friction plates.
Do you get what i mean?
Drill 1/8 " or 3mm holes in a spiral sort of pattern, Google Sigma race clutch pics to give you an idea if you're unsure.
Slightly countersink all your holes so steels won't drag in hub grooves, use a fine file on inner side of hub to remove any drilling swarf bits, if friction & steels have left any ridges, i tidy them up with 800 grit Wet n Dry wrapped around a smooth file, avoid taking too much alloy off if poss, or you'll add extra back lash into transmission.
Rebuild clutch (replace hub nut)
Fresh Synth oil & filter, new cable if its dragging.. M&P do a good pattern cable, just like a Yamaha one with mid cable slack adjuster.
" SIMPLES"