[Closed] bottom bracket and chain guide help

Guys,
I have a SM-BB70 bottom bracket on my specialised enduro and when I position the crank arms horizontally and wiggle them side to side I can feel some play in the bottom bracket so I'm guessing its time for a replacement.

Do I need to replace it with the same SM-BB70??

Can anyone recommend a good value bottom bracket mount chain guide, I do not have the threaded holes on the bottom bracket so it needs to be one that is sandwiched between the frame and the outer BB cup.

Is it as simple as it looks to change a BB,
Undo and remove cranks
Use BB spanner to undo the outer cups
Withdraw the cups and inner clear tube.

Do I need to grease the bearing prior to refitting, and do I grease the threads before fitting?

Thanks for your help.
Col