[yorkie_chris]

Wire brush the loose stuff off and leave well alone unless you really need it off. gob everything in ACF50.

Biggest reason for needing to take pipes off is to remove swingarm to do bearings.

They fuse into the head. Nuts are a nightmare... Nibble the nuts off with a grinder and tap them round with a punch to save snapping the studs.
Exhaust will be seized into the head from galvanic corrosion between the steel and ally. Get a piece of wood against the exhaust and give it a good clout one way then the other to wobble it free.