My wife and I are booked PVG-HKG-LGW on 6 Feb in econ Q. It's the return leg of a LGW-HKG-PVG-HKG-LGW booking. The flights are KA805 PVG-HKG 6 Feb, CX343 HKG-LGW 7 Feb.

My understanding is that booking class Q doesn't allow upgrade with points, which is a pity because some unexpected work commitments on arrival mean that I'd like to upgrade to J.

Questions:
1. Is there any way at all to upgrade this booking to J (even just the HKG-LGW leg)? Partially or entirely with points is preferable, but I'm also interested in whether it can be upgraded with cash.
2. Can the route for the second leg be changed to HKG-LHR? I tried to use the "change flight" function under "manage my booking" on the CX website but it only offers other times for the same exact routing.