Installing an SSL Certificate in cPanel requires that the domain be assigned a dedicated IP to begin with, so check your cPanel or with as to your IP status. Secondly in order to use the "SSL Manager" Feature in cPanel a Dedicated IP is required, So check with to provide you with a Dedicated IP, the cost of the IP and the activation of the "SSL Manager" in cPanel if it is not already in place.
Taking the next step now that everything is place we will click on the "SSL/TLS Manager" icon located on the cPanel "Security" panel. This first step needs to be completed BEFORE you can purchase the SSL certificate from or SSL Provider.
Click on the link below "Private Keys (KEY)", on the next page go down the page until you find "Generate a New Key". In the empty "Host" field enter your domain as you would like it for the SSL Certificate. NOTE: You have a choice of selecting your SSL with or without the "WWW" preceding the domain name. This selection is important as an SSL will ONLY work correctly under the format that you select here. If you choose to use https://www.yourdomain.com, your ssl will error if you use it as https://yourdomain.com (without the "www") or the other way around. Most web owners and users select to use the SSL with the "WWW" in the cert name. Change the KEY SIZE to 2048 and Click The Generate Button. You will then go to a page displaying your Private Keys, While this will be passed on to the next step "Certificate Signing Request (CSR)" it is a good idea to copy the generated key in the top box and paste in notepad until you have completed the ssl set-up. Copy EVERYTHING in the box including the "Begin and End Comment Lines". Click "Home" at the top of page.
Now Re-Click the "SSL/TLS Manager" icon. On the Manager Page Click on the link below "Certificate Signing Request (CSR)", you must generate a CSR to take to the SSL provider that will issue the certificate. To Generate a new CSR make sure your domain name as you created it in the Private Key is visible in the HOST field dropdown. Continue by filling out the information requested. NOTE: You have a choice of selecting your SSL with or without the "WWW" preceding the domain name. This selection is important as an SSL will ONLY work correctly under the format that you select here. If you choose to use https://www.yourdomain.com, your ssl will error if you use it as https://yourdomain.com (without the "www") or the other way around. Most web owners and users select to use the SSL with the "WWW" in the cert name. Continue to fill in the information as requested and Click the "Generate Button". On the next page you will be presented with your "SSL Certificate Signing Request". COPY ALL THE INFORMATION IN THE TOP BOX and paste it into that Notepad you saved the KEY in before. You will need to take this CSR to the issuing Authority of your SSL or to for their assistance.
Once you receive your approved and completed SSL certificate from your SSL provider login or return to the SSL Manager and Click on the manager icon and on the next page find the link below the "Certificate (CRT)" heading . Paste the new SSL certificate you just received form your SSL provider in the space provided and upload. Click the return to SSL Manager at the bottom of the page.
Next we come to the last link on the Manager Page. Activate SSL on Your Web Site (HTTPS). Click and follow to the next page. Find your domain in the dropdown box and cPanel will (or should) fetch your SSL certificate and all other supporting documents and fill in the large boxes. once it has completed, go down the page to the "Install Certificate" button and install.
Your SSL Certificate should now be set up and functional in a short period of time (some propagation maybe required).