We have 3 screens and would like replace with 2 screen (https://www.bunnings.com.au/estilo-1830-x-830-900mm-x-855-880mm-chrome-shower-screen_p0012606)
1. Is it ok to replace 3 with 2 screens. Anything I need to worry about?
2. How easy/hard it is to DIY. I am pretty handy and comfortable doing repairs and replacements, however, never done shower screen replacement.
Welcome to the Bunnings Workshop community @Skyisblue. It's terrific to have you join us, and many thanks for your question about replacing a shower screen.
You could certainly have your current shower screen replaced with a two-panel option. Since this is a hobless shower, there needs to be a water-stop angle that prevents water from creeping out under the bottom rail of the frame. You won't be able to use the existing angle and to install a new one, you'd need to re-tile the area. This potentially leads to needing to re-waterproof the stall, and to do so in one continuous layer would result in waterproofing and tiling the entire bathroom.
I wouldn't say it's a complex assembly and installation process, but the bottom rails must seal against the tiles adequately. Given the need for a water-stop installed by a qualified professional, I suggest considering whether you'd be better off making this screen change during a more extensive bathroom renovation.
Let me mention one of our very knowledgeable members @Vis-á-vis to see if they have some thoughts.
Please let me know if you have any questions.
I think Mitchell has covered everything.
If your shower screen was installed correctly with the appropriate waterproofing then you'll likely find a waterstop protruding out between the tile grout line and into the bottom of the frame. If you remove the existing shower frame then you won't be able to replace it without taking up all of the floor tiles, which then means you'll have to take down the wall tiles in order to have a continuous waterproof membrane.
In short, I think this is probably something you should leave until you renovate the entire bathroom....as Mitchell has already said.