It'll be easier to replace it from the top. So, don't remove anything and do it from the bottom of the vehicle. To get to it there are only a few heat shields in the way. The only time you'll need to get under it is to remove the third bolt on the bottom of the housing that is by oil pressure switch. You wont have to remove anything, just reach by the subframe to get access to the bolt with a socket extension. You also don't have to remove the housing completely from the vehicle and can easily replace it by pulling the housing back slightly.
Here is the gasket if needed:
Mini Cooper & Cooper S (R50/R52/R53) - Oil Filter Housing Gasket
This video should help: