Any computer shop will do it for you, at modest cost, I'd guess.
Or you can do it yourself, probably. During boot it may suggest you press a PF key to get into a recovery dialogue, which may offer you the option of resetting to factory, as-new configuration. One of mine did, I took the chance and it worked OK.
I am lucky, though, I use a normal desktop machine routinely, the laptop is an 'extra' and I didn't care if I messed it up. It was already useless.