Ah yes, that way. The Ruckus SE informed us that it's only possible to go back 4 releases. Eg 3.0 - 3.4 .. not 3.0 to 3.5 .. I have no idea if this is correct or not.
Upgrading is a fairly easy task. Just download the Ximg file of 3.4 and upload it to the upgrade tab. The system will selfcheck if there are any issues. You do have to take in account some things. 1) You will probably need to increase the memory2) yo...