Topre spacebars are a little bit more complicated to take off than MX spacebars.
1. Take off the alt keys
2. Push the left side of the spacebar down, use your right index finger to lift up the right side of the spacebar from the bottom until you hear the stabilizer click (means that it's off)
3. Repeat for the left side
4. Use both index fingers and evenly pull both sides up
5.
6. Profit! (or maybe not, if that doesn't fix the spacebar)
Good luck! And don't lose the spring underneath the spacebar.