They must be done correctly! if not, you will be left with a "ledge" of porcelain at the gum line which will trap bacteria and illicit gum disease.
I would absolutely recommend porcelain veneers over Lumineers, especially on lower teeth. Lumineers are a brand of prepless veneers. While some veneer cases can be accomplished with minimal preparation they are rarely no-prep as advertised especially since the lower teeth need more room so as ...
If you mean take them out to clean, as in nightly like dentures, then you did not get Lumineers®. Lumineers are bonded in place and can only be cut off.
If you mean how often would you need to replace them (cut them off and get new ones), then that is up to you. If...