Change an installed certificate

I have a new customer needs to change his Thawte certificate with Comodo EV certificate, his certificate is valid till 07-2009, he wants to create the CSR to go through the process of issuing the EV SSL certificate.
To create the CSR, he has to delete the current certificate, I told him that he should take a backup from the certificate before doing this, and restore it again after creating the CSR, till we validate and deliver him the new certificate.
the question is, after creating the CSR and restoring the old certificate into the server, the request of the new CSR issued by the server will be deleted too, so it will not appear in pending process.
So, if the EV SSL certificate is ready to be installed, can he delete his current Thawte certificate and create a new CSR that will be matching with the new Comodo EV Certificate?

Hi,

To buy Comodo EV SSL certificate, you need to create the new CSR with KeySize as 2048 bit.

Get help from our Knowledgebase article to create the CSR without removing current certificate.

For more help, you can get the LIVE chat assistance from www.instantssl.com