MANUAL installation update from CMS 2.3.7 to 2.3.11

CMS 1.8 to 2 version upgrade step by step

This article will apply to you.
But if you tell me what the operating system is before. It would also be helpful if you could tell whether you are using Apache, iis or nginx. It actually doesn’t change much. just follow the instructions. I can help you faster if you explain where you are stuck.