To remove? To open?
If they’re painted shut, then get a thin putty knife.
If the house has settled and they are “wracked” then they may not come open until you fix the structural settling in the house.
Run the putty knife between the sill and window on both sides. Once open put a dab of oil on track and slide window up and down a few times to lubricate the tracks.
Don't use oil. It attracts dirt and gets sticky over time. Use WD40 and spray the tracks using the supplied straw. Give it a few minutes to soak into tight spots.
Hey Clayton: Here is a site that may help:
Once you get it unstuck, use white lithium grease or a spray silicone which does NOT gum up tracks ect, like WD-40.
One guy said "Be careful if they are older windows. I lubed up mine in my house. Well I did it to one an then realized NO NO NO. I used wd40 and sprayed it in the tracks on the springs etc. Not a great idea. 1st check how much play the window has side to side. I know it sounds strange IE Why would one lube a window that has play in its movment. Well even if it has play side to side does not mean it will move up and down easy. Anyway short story short. After I lubed it up. I opened the window and it slammed shut as soon as I let it go. I was very lucky in that my panes did not break. But learned a very good lesson. Lube up too much and you could be putting in a new window anyway."