I am currently using Cloudflare CDN on the wordpress website but having a lot of issues in website accessibility. I have decided to use Let's encrypt SSL instead of Cloudflare. I need guidelines how to shift my server to Let's encrypt. Thanks
Welcome to the Let's Encrypt community @BrianParker
Let's Encrypt is only a Certificate Authority (CA) that issues certs. It does not provide any connectivity services.
Currently, the CDN is responding with its cert from Cybertrust. And, someone has been requesting Let's Encrypt certs as well. See these certs here. You have not said how these Let's Encrypt certs are already used (or if they are).
I doubt switching off Cloudflare CDN will resolve "accessibility" problems. But, we will need much more info to advise. Can you provide more details of the problems you hope to fix?