Need a locksmith to replace a door lock in my flat

I recently moved into a flat and need a reliable locksmith to replace the existing door lock. The door is a standard UK exterior/main entrance, and the current lock feels stiff and somewhat worn. I’d like a secure, up-to-date cylinder installed, preferably a five-lever or British Standard lock. Please confirm compatibility with the door, bring all necessary tools, and provide a short warranty on the workmanship. Availability on weekdays, and a quick turnaround would be ideal. I’m located in a ground-floor flat with easy access to the main door.