How to use smaller dose pen

Hey all

I have been on Ozempic since October 2025. I had been on 1MG for a few months now but I have 2 or 3 of the 0.25/0.5 pens left. I’ve been researching how to use them and I’m getting conflicting info. I know I can use the 0.5 2x to make 1MG but what I don’t know is do I keep the needle in and do 0.5 back to back or do I need to do it on each side. Any advice is appreciated