How to add mesh to the third person character

Can any body guide steps to use a mesh and join it properly to the third person default character .

open your character skeleton . choose any of bones you want to attach a mesh to from the left side hierarchy and right click on that bone and add a socket and name that.

you can add preview asset to set its transform

then you can spawn a mesh and attach that to that socket you created

Thanks for advice saeedc.