Welcome to the Workshop community @Benk1.
Our helpful community members are going to need a little more information in order to assist with your question.
Could you please add some photos to your post or to a reply below? Some images of the lock will really help other community members provide some specific advice.
Please let me know if you have any trouble adding the photos.
Hi @Benk1. Thanks for updating with an image to assist us.
The easiest approach is to replace the handle with the same model. Please have a look for any identifying brands or numbers on the handle assembly. If there are no identifying marks, remove all retaining screws from the mechanism. You may find screws hidden under caps or if you open the door where the latching mechanism is.
Take the handle assembly with you to your local Bunnings store. A team member in-store will be able to match it to a suitable replacement. We need a similar unit that suits the same thickness as our current door. Ideally, we would also like the same mounting hole positions. Units will come with a mounting hole template, so if we can't find an exact match we should be able to reposition the holes with a drill.
If the mounting holes match, simply line all the holes up and install screws to hold your new lock in position. If they do not line up, adhere the template to the door and drill the new holes to match. You may also need to cut the lock bar tab to size and there will be specific instructions included in the kit to do so.
If you have further questions about replacing the lock or need assistance, please let me know.