how to remove hook guide

Step 1 says to remove old hook guide, but doesn't explain how. I've tried tilting it in and trying to pull it out that way, but it won't budge. This shower is about 25 years old and I'm guessing the doors are as well. Any advice you have would be great. Thank you.

Thanks for your response. No, they are not that specific model #, as these doors are old and so are the hook guides. The model 10-139 is the closest I could find to the guides that are on my door (same dimensions as well). The screws fell out, I moved them away from the door and tilted them to get them off the track, but they will not come out. I even tried to pry them out...didn't help. I was hoping there was a trick I was missing, but it doesn't seem so. I appreciate your quick response.

I hope these photos came out well enough. Let me know what you think.

I posted these through my phone, but just in case they didn't go through, I'm trying again on my laptop. Let me know what you think. Thank you.

Thanks for your help. I decided to keep the old ones in and just drill new holes. Works fine. I have a feeling these hook guides were installed as part of the frame, so they don't come off unless the frame comes up as well. My solution was much simpler. Thank you!