Welcome to the Bunnings Workshop community @thein. It's fantastic to have you join us and many thanks for your question.
Applying silicone is a relatively easy job to do yourself as long as you follow some directions. Here's a helpful step-by-step D.I.Y video on how to silicone a gap which I trust you'll find useful in the process. Make sure to remove any old or damaged silicone prior to applying the new seal to make sure it has a great bond.
We look forward to hearing all about the projects around your home and garden and I trust you'll find loads of inspiration for them from within the community.
Please let me know if you need further assistance or had any questions on the process.
Mitchell
