Can I rekey it to match an existing Kwikset lock that uses a KW1 style key?

This unit can be rekeyed to match any KW1 key from any brand. Simply call your local Lowe's and speak with the person that does the rekeying usually in Hardware. They will be able to tell you when they are able to rekey your Gatehouse lock and list each item to bring before you arrive. If you have any further questions, call our customer service help line at 1-877-4GATEHS (1-877-442-8347).

I'm sorry, but there is not enough information provided in the question. Manufacturer and model number would be very helpful.