Analyze any Binary file of Packages

[BatFan]

Once you have selected this memory in listing window you should see 'XREF'. if you have XREF[3]: or maybe XREF[5]: it' mean that you have 3 or 5 referenced adresses of this mesh part that you find in reseach memory string before. So double-click on on XREF and your next window pop up.
You should see that it is DATA type. So in my case it looks like 'Helm Front' that is divided into 3 parts of 3 adresses, so we can say if we deleted it in HexEditor this character lost mesh from front side on helmet.

Okey so now we know where it's stored. Open Hexeditor (not the hexeditor inside) and select it that we find in Data before.
Okey instead delete replace it with empty bytes that does nothing (00).

[BatFan]

Man, sorry to disappoint you, but Hydra is CODE reverse engineering tool, what means - disassembler. Upk/uasset files has no machine code inside, what could be analyzed with disassembler, and you're trying to treat Unreal DATA as code. Of course it will show you some "xrefs" because large block of binary data will have values which are close to random, and these xrefs might randomly appear. Hydra can also show you data as code (you'll get entirely garbage code), but just because it will try to consider data this way. If you'd know basics of Unreal data formats, you'd understand that these "XREFS" can't be applied to Unreal data.

You saved my time because it didn't make sense what I done, but soon I get another idea in which way mod 3d object stored in game archives in the unreal data.