Well I was grossly simplifying the process, it could very well involve changing some hardware chips against new ones.
Since ownership can be transfered easily in a process that takes about 1 minute, I doubt the chips are read only, yet they might well be encrypted and exchanging them might be the only way. But as you said, we dont have Data Trails yet, so every GM has to find a solution that fits for them.
All we really know is "it takes this long and it doesn't cost any nuyen" (at least not significant enough to mention it) but not what's actually involved. If it requires matrix access is apparently up for debate.
But yes, you won't make tons of money from the loot usually. If you're lucky, then maybe cyberware will fetch a neat coin, and also has the advantage of being fairly sure that the owner is not coming after you anymore
But weapons and stuff? Maybe not.