Cathay Pacific Asia Miles - MAN-LHR-HKG Where do I get my boarding pass after OLCI?

I'm flying MAN-LHR-HKG in a couple of days and am thinking of OLCI. This will be my first time doing this and it seems I can only OLCI the LHR-HKG leg on the cx.com. I was wondering do I collect my BP for the LHR-HKG leg from Manchester or from Heathrow? The MPC agent on the phone told me to collect the BP from LHR but check my luggage all the way to HKG from MAN. If I have to get the boarding pass from LHR, where do I get it from? Do I have to go landside and get it from the CX check-in desks or can i get it somewhere airside?
As you can see, I'm new to all this OLCI malarky so have no idea what to do. I normally just check in when I get to MAN and get issued with both BP but thought I'll give OLCI a go and see what it's like.

Thanks

you should'nt have icheck as the agent might not be able to give u a bp at man. i did something similar on fri - hba-mel-syd-hkg. the cx cso told me i shouldn't icheck if i want my bp at hba - it can cause problems with the boarding sequence.
ur baggage is different because it is independent to the bp and u can check it right to hkg from man

MAN airport has a transfer desk, which can issue your boarding pass MAN-LHR (presumably on BA and in T3). You don't have to go landside. They probably cannot handle LHR-HKG -- the transit desk at MAN is a bit inept. You can easily do that at LHR, just have proof of travel such as your ticket number so you can clear security (otherwise they will force you to go landside and check-in at the CX ticket counters.

No particular need me to get my boarding pass until I get to LHR as long as I can stay airside at LHR (the bus is much faster than walking) and get my BP from a transfer at LHR T3.

Many thanks