Uninstall old Android SDK versions
Just delete the packages you want to uninstall.
You may still want to retain some of the older SDK's so as to try your apps on lower platform. I personally keep GB(API 10), ICS(API 14) and JB(API 17).
Also what you can try is just move the whole android SDK folder to a new location with relatively large storage, and then specify the new path in preferences in eclipse. Will save you some bandwidth, in case you later need those API's. My friend just copies from mine. Data here is very costly :(
You can deploy it, but you would have to mention it(that you want to run on lower APIs) on your manifest file. Also any API above the targeted device will not run and will interfere with your app design. Search for android TargetSDK version and MinimunSDK version.
Select the packages that you want to uninstall
and click delete packages button.
As for the current version (Feb 2019) here is way that works from within Android Studio:
Open the SDK Manager (Tools -> SDK Manager).
There you see all available platforms and in "Name" a box whichshows Installed [✓], Update available [–] and Not installed [ ] platforms.
- If you klick on that box you can change the status. Click until it is empty and a red x shows up. Then press Apply. The platform will be uninstalled then.
