It may depend on the lever, but in most cases, yes. The lever is held on by a band that wraps around the bars, and you can remove the lever body from the band by unscrewing the bolt hidden behind the lever. Then change the hoods and reinstall the lever body. Similarly, you can use this method to change your handlebar wrap without the risk of tearing the hoods (which can often happen if they are no longer supple).

I wouldn't paint hoods, but some people have had success using Plastic Dip to rejuvenate hoods.