Though I have seen this type of problem in other drive models, I don't recall on this drive. So, likely I did not have the pleasure of testing on this particular model.

So, yes, head stack removal is not possible with traditional method for this model.
I suggest using the upper surface to your advantage in ensuring the platter is placed on the drive as gently as possible. Since the top surface is not used, you can dance to MC Hammer's "Can't touch this" all you want on it. So, use that to your advantage to put the platter back in place.
Additionally, to further reduce the potential impact between the platter and the head, I would recommend using a thin paper with a smooth waxy finish cut up to fit and remove properly from the disk. Lie it on top of the head, then place the platter gently in place. Then slowly and smoothly pull the paper out from between the platter and head.

P.S. Humans are biased as they are poorly programmed on perception. Perception is reality. In your circumstance, my critique was a bit strong, sorry. For 99% of other first posters coming to the site, different story.

I can remove the platter, replace the head. Up to this point no problem. But if I try to put the platter with the head in place I am almost 100% sure I will damage its surface as I have no way of making sure the platter wont touch the head.