You need to install the mounting brackets under the car and also the trunk reinforcement plates in trunk (floor).
Here is the kit from Brad Mayer (no affiliation). Looks like it comes with instructions.
https://914ltd.com/product/porsche-914-orig...way-bar-mounts/This requires welding and protection of the metal after welding.
Once this is done, you need to swap the lower shock bolts (something you probably figured out). Then install the bar.
The drop links can require some force to pop onto the spheres but this can be achieved with a large C clamp. I know there are threads here somewhere. You will want to put grease in the drop link bushings. Another trick that was shared here is to drill a small hole in the center of the drop link bushings to allow air to escape as you are pushing them on the spheres.
Hope this helps!
Good luck with your project!