House Ownership Vs Will - What Outweighs In This Messy Situation

Please please help, I'm in desperate need of advice and possibly have only a few weeks left to solve this.

Background- My last grandparent has passed. Way before their passing, the house ownership was transferred to all of their kids (so they each owned an equal portion and the house is fully paid off). Out of all the kids they had, one had passed prior to their parents passing and prior to this, they signed over their ownership of the house to several grandkids. So a portion of the house is now split further.

One of the grandparents kids has been "living" in the house before the passing of my grandparent, but also still rented their own apartment. They now think they are entitled to everything and have the say in the matter. However, there is one executor on the will and it is not that person, but a different kid of my grandparent.

The will does not state who gets what in any manner. It only says that possessions will go to their kids. It was agreed upon that kids will go through the house and then grandkids are welcome to look through after. However, grandparent was a hoarder and the kid "living" in the house is an awful person and has been getting rid of things and donating and keeping things out of spite (and also a hoarder). It has been impossible to clean it out as a family because of their insanity.

Location: MN

Questions-

-I legally own a portion of the house, so does me owning the house mean I can legally break into it if needed?

*Does legally owning the house mean I have a right to any possessions or does the will outweigh this?

-The house is now in progress of being sold to the awful person in it, it is not officially sold yet. Does this change anything with my previous questions?

-Once the house is sold, do all items now belong to the relative who bought it, or does the executor of the will still have a duty to delegate any possessions?

-Items have unfortunately been hidden or walked away by the awful relative and others, is there any legality to proving this if they weren't the executor on the will, or is it just how it is now?

-I did have a few of my own items in the house and the person living there claims they gave me what was mine, however, do I have a right to walk through every room to verify since I still own a part of the house? (They are very hostile and don't want people going where they are already moving their stuff in to, which is how we learned things are being hidden). -Would a cop be best to help with being in the house? Or a lawyer?

It is quite the sad ordeal because the few grandkids only want a few smaller items for sentimental value and the awful relative does not care one bit. The executor of the will also struggles with being assertive and has basically folded to the awful relative. I could really use some help and advice. If you've read this far, I appreciate you. Thank you.