For the 105xx platform there is no software-only upgrade to Comware 7. It always requires to change at least MPU, sometimes LPUs as well. In your case it is just MPU, because both LPU types and Fabric module are compatible with CW7:
HP A10500 Main Processing Unit JC614A - not supported by CW7
HP A10500 48-port Gig-T SE Module JC618A - supported by CW7
HP 10500 4p 40GbE CFP SF Module JG396A - supported by CW7
HP 10508 1.92Tbps Type D Fabric Module JC754A - supported by CW7
You need to replace currently installed JC614A MPU with one of these:
JG496A: HP 10500 Type A Main Processing Unit with Comware v7 Operating System
JH198A: HP 10500 Type D with Comware v7 Operating System Main Processing Unit
I suggest you to contact our Sales for and discuss with them your requirements, because since it will be an upgrade with downtime, it might be a good opportunity to revise your current configuration and check what else can be improved and/or adjusted according your specific needs.
Hope it helps!