Cartridge mounting

Can any of you seasoned pro's give me some tips/pointers on cartridge mounting? Music Hall is sending me a new cart to replace the stock one on my MMF-7.1. Hopefully this will fix the channel inbalance problem I've been having. They are sending the low output version of the Eroica. I've mounted many a cart in the past, but they were on removable headshells, which makes the job a bit easier. Also, they had replacable styli, so you could remove it while mounting. With a fixed headshell/stylus do you do the wires first, or loosely mount the cart first? Don't want to &*$% anything up.....

Any tips would greatly be appreciated.