LS Enterprise to OLS

I enabled the free (1 domain) licence for Litespeed Enterprise thinking it would be just for 1 domain, clearly I was wrong.

I have 4 sites on the server, 3 work fine but a 4th says “License Limit Reached”

Is there any way to downgrade to OLS? Or have I stuffed my server?

If I make a backup of each website will that save all the emails and all that technical stuff too?

Sorry but im a rookie and need some advice.