Yep, did one from 6.2.6 so no problem with that version. You need to go v7.0.1 to v7.5.4 then v8.1. Just read the documentation (the upgrade guides detail the steps very well). Then plan it out. Best way is to get a copy of the database onto a virtual platform - you can then upgrade (as if for real) and then detail the steps in a mini-plan. I always do this and, also, you can then build a bundle that you can install post-upgrade (with your customisations).
So:
1) Install live DB in test env
2) Use Architect to delete ALL non-released plugins (as they're not used, but will confuse)
3) Apply the upgrade fully
4) Use Architect to delete all non-released Saleslogix plugins (but not yours)
5) The balance will then be:
i) Saleslogix plugins replacing your live plugins
ii) Your plugins, but de-released
6) You then go through another pass - take each of the current slx plugins that is a duplicate of yours - then modify that to include your customisations (you can use BeyondCompare for this)
7) Save the plugin into a new project/bundle - this is your overlay for later
8) Perform the upgrade live (preferably after testing to death at (7)
9) Apply the bundles as per the upgrade guides and when directed
10) Install your overlay project bundle from (7). Job done !
