No problem, I hope it help, and have fun.

it works! thanks dude!

Now once everything it's done it should look like this
https://sp.zhabite.com/sharedfiles/filedetails/?id=2643108704

5. Once you at the local l4d2's file search for left4dead2 > addons > workshop > then find the Medkit VPK file by:
looking for the picture of that medkit mod, and you look for the numbers for the VPK file, it should be the same number, then you'll double click the VPK file. the GCFSCape should help you open it up and now you'll be able to extract it by simply drag it into the STEP 3 new folder file you just created.
6. Get into your step 3 folder > models > then DELETE w_models. then just leave it.
7. Go back to the l4d2's local file get to > bin > look for that VPK that I told you to remember about repacking it.
8. Finally drag the STEP 3 new folder right at the VPK it will automatically repack to VPK.
9. Lastly once the file repack to VPK file, drag it into your: L4d2's local file > left4dead2 > addons folder. DO NOT put into workshop.

So let's start with step by step:
1. Go find your Medkit you wish for the first-person view, and subscribe it, Example we will try with
"TWD medic bag" by Oguzhan
2. Then open up your L4d2, wait till all the Mods is loaded, and uncheck the medkit mod you just subscribed, to avoid conflict. Then quit.
3. Now, create a new folder at your desktop, rename to whatever name you wish i.e TWD_medic_bag_noworldmodel >> then leave it will get back to this soon.
4. Head to your L4d2 local file location i.e: go to steam Libary - right click L4d2 - Manage > Browse Local file.

Sure, I can help. First thing first you need two things.\
1. You need GCFScape for extracting VPK files Link :
https://nemstools.github.io/pages/GCFScape-Download.html

2. Go to your L4d2 local file example: Steam library > right click L4d2 - Manage > Browse Local file, and search for bin > look for file name VPK. This you will need to remember where to repack the file back to VPK.

How did you do to replace it? Can you explain more detailed for me?