Web Server Expired Certificate

I have a situation  which may be a simple fix, then again it may not.

I have a SBS2008 with an expired web server certificate. 

It started with the remote server certificate which was fixed, but now the web server is not allowing us to remote in to sharepoint files.  We can get to log into local computers, but we can't launch outlook email from the internal website at the remote workplace or get to the internal website. 

Could I get the steps to create a new webserver certificate? 

Thanks,

Latrice