How do I repair my kettler condor cross trainer

What's wrong, is the readout simply not working? If thats all it's the battery, which is easy to replace but a little harder to find. Just in case it's the battery I'll paste here my solution:
If you look behind the unit, (directly behind the digital readout) you'll see a small rectangular inset, if you look up in that (I used my cell phone light), you'll see a tab that you can pry with a screwdriver gently to release the computer section. Just keep one hand on top, when you pry it you'll feel the unit pop up, then you can lift it out. It takes 2 AA batteries, thankfully not some bizarre disk batteries :)
Btw when you look at the readout, you'll notice it's set in a silver square- that square is the computer module that pops out.
Hope this helps!