Every time i have written something to flash it had erased the previous contents. Therefore i would suggest copying current flash contents to a TFTP server, erasing flash and then copying both old contents and QDM to the flash from TFTP server.
I don't have experience installing QDM though, so i would suggest checking out installation guide.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...