STFM with 6 chip TOS. what are the jumpers for 2 chips?

i have an STFM with a 6 chip TOS 1.02 and i want to update to a 2 chip 1.04 version (still the same 28 pin version)

i thought it was the 2 or 3 solder pads marked 256K that needed to be moved to 1M

is that all i need to do?

tried it today and no joy

is there something else needed?

thanks :0)