With a shimano bb facing isnt as critical as they use plastic ‘top hats’ on the bearings so any slight alignment issue will be taken up, if i were using a hope bb i’d probably get it done though.
In short, you dont need your bb shell faced, you’ll need a crank extractor to take off your old cranks and a sq taper/splined bb tool to get the bb out, you just need a hollowtech 2 bb tool to put the cups in and a tool to tighten the bearing pre-load cap. X-tools do decent stuff, if you’re feeling flush then go for Park Tool.