Run the plugin
Install the plugin, than make sure that the Engine content and Plugins content are visible. Then locate the Skeletal Mesh Merger Content folder and right click to GlobalMerger -> Run Editor Tools
2. Run the Merger
Add all the meshes you want to merge in to the MeshesToMerge array.
Optionally set the Skeleton property force the final mesh to be assigned to the skeleton .
You can eventually strip the highest LOD of the meshes to merge for further optimization (StripTopLods).
Select the path Relative to Content/ in which the final asset should be save and the Asset Name (make sure the asset name is unique!).
Then click the RunMerge button.
You can eventually fill the MeshesToMerge to merge by parsing all the Skeletal Mesh Components of one of your actors in the scene. Just click on the color picker,
select the actor and click on FillFromActor button.