Managing Thread.CurrentPrincipal

I have WPF application which have a log in form to enter user name and password. The app allows to sign off of current user and sign in another user. I use Thread.CurrentPrincipal (ClaimsPrincipal) to store user identity (ClaimsIdentity). When current user logs off and new user logs in I want to remove old user identity and create set user identity to Thread.CurrentPrincipal, however there some limitations:

- Thread.CurrentPrincipal can be set only once

- ClaimsPrincipal has no method to remove an identity from Identities collection.

So what's the best practise to manage Thread.CurrentPrincipal when multiple users can sign on per process?

Thank you in advance,

Artur