Double manning next week. any basics i could get given would be appreciated 
make sure he dosent snore in case your on nights out 
For both drivers to come under multi manning rules they must finish at the same time and must be together within 1 hour of their starting times
The shift can be a max of 21 hours and a 9 hour REST must be taken within 30 hours of the start time - that 9 hour REST is considered a FULL daily rest
REST can only be taken in a stationary vehicle
BREAK can be taken in a moving vehicle
The first 45 mins of POA when the card is in slot 2 will be regarded as BREAK
The one actually driving must have their card in slot 1
Does that help?
super thanks : 
If it’s someone you already know and get on with then great, if not you’ll probably want to punch them or leave then somewhere far away halfway through your shift.