Hi @Nj2,
Welcome to the Bunnings Workshop community and thank you for your question.
Start by having a read through How To Paint a Door as the process is essentially the same with a few intricacies due to the hardware and glass.
I would start by removing the door handle and then taking the door off its hinges and gently setting it down on a flat surface such as a workbench or two saw horses.
You should then protect the glass using a combination of masking tape and masking paper. This will help to prevent any damage during the preparation process and the eventual painting.
When the glass has been covered, give everything a light sanding with some 120-grit sandpaper. As the current paint looks to be in fairly good condition, there is no need to remove it completely, but you'll want to smooth out any uneven surfaces and buff the old paint.
Once sanded, give it a good clean with sugar soap to remove any remaining dirt and dust and prepare the surface for the next steps.
After this, the process is the same as the article above. Apply an undercoat such as Dulux 1Step Prep Primer, Sealer & Undercoat or Taubmans 3 In 1 Interior And Exterior Primer Undercoat Sealer, using a combination of a Paint Brush and a Paint Roller.
After the 2-hour drying time that is required by the undercoat, you can apply 2 coats of a suitable paint such as Dulux Aquanamel or Taubmans Water Based Enamel in a colour and finish of your choosing.
Once the paint has dried, rehang the door and reattach the door handle.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
