Hi Everyone,
I haven't had a chance to post this up yet on the communities. However, back on GA of vSphere 6.0 I developed a nice how to guide on replacing certificates in vSphere 6.0 and I wanted to share it with everyone.
vSphere 6 - Certificate architecture (What's new), VMCA Subordinate Certificate, Machine certificate replacement, and Solution user certificate replacement
ESXi 6.0 Certificate replacement
http://www.virtually-limitless.com/ssl/esxi-6-0-ssl-certificate-replacement-and-management/
Sorry I hadn't posted this sooner, but looks like a lot of people are successfully following through the steps!