No need remove the brake cap, it's vented.
You could remove the cap on the tank to release pressure - the Scoob does build some, but as you unscrewed the sender unit it would release slowly anyway. Always do this job in a well ventilated area. Best to put any fags out too.
No need to remove the fuses or relays Kenny, keys out would suffice. Petrol's bloody dangerous. Still don't like working with petrol