From the author's README on Thunderstore

Bam Margera from THPS 3+4

Model is taken from THPS 3+4. Face animations are disabled because the game's art style (and animation) doesn't match the realistic faces from THPS 3+4.

ATTENTION

To display the model correctly, go to the character settings in the game, open the APPEARANCE tab, and set these values for the body:

Height - Any value
Build - 3
Chest - 0
Hips - Any value
Back - 0

In game

To select the character in the game, go to the character customization menu, open APPAREL, and then open the Costumes tab.

Installation

Install this package using the ReSkate launcher, enable it, and launch ReSkate.

Install Bam Margera

You need ReSkate and your own copy of skate. on Steam.

Open ReSkateLauncher.exe and go to MODS.
Search for Bam Margera and click install. The launcher also installs anything it depends on.
Press PLAY. In game, the MODS tab of the ReSkate menu (Insert) turns it on and off.

Or install it by hand: download the .zip and drop it on the launcher window, or unzip it into its own folder in Mods\ beside Skate.exe.

Maps show up in the ReSkate menu's level list. To join a server running a custom map, you need the same map installed. If the game won't load after installing, see known issues.

skatemods doesn't host or review this mod. The download comes straight from Thunderstore. Only install mods you trust, because scripts can run code.