I recently signed up for the Adobe CC for Photographers and upgraded Lr from v4.3 to v5.3. My computer has a smallish SSD for the system drive and I'd like to conserve space on it by removing the unused copy of Lr.
What is the best way to remove the Lr4.3 copy without screwing up my 5.3 copy, catalogs and plug-ins?
You should be able just to remove LR4.3 (from control panel / programs and features), however, your caution is well advised. When I removed LR4, it de-licensed my CC version! You could always install LR5 again if this happens (remove it using control panel, wait until the CC app notices - might have to reboot - then re-install from the CC app). However, what I did: before removing LR4, run the CC version of LR5 you've installed, go to Help menu, Lightroom registration..., licence tab, and note down the licence number. This is your LR CC licence. (It's not the same as your LR Photoshop licence. Don't ask me why not.). Then if LR CC asks for a licence, try that.
Catalogs are never removed when you uninstall LR, but for safety's sake, make sure you have a backup. Plug-ins, presets etc: good idea to back them up, too. For the locations, see
http://helpx.adobe.com/lightroom/kb/preference-file-locations-lightroom-41.html
