Yep, whatever you want to remove there’s always something else that needs removing first.
Another couple of things:
1) When you refit the cover be sure to grease the splines on the gear change shaft to avoid damaging the o-ring. Grease that as well.
2) Don’t refit the cover with the oil pump still in. If it doesn’t align with the slot in the gear shaft it can break when you tighten the cover bolts.