How to publish an article from our thesis, as the thesis is already submitted in Higher Education Commission Repository?

I want to publish an article from my graduation thesis, but it is submitted in online repository of our university to the Higher Education Commission. Once the manuscript is checked for its similarity index through online plagiarism check , there arises the 88% similarity in the report from the same thesis submitted in a repository.

Now I want to ask following questions;

1. should I submit the manuscript to a journal for its publication as it is?

2. or I should rephrase / rewrite all the manuscript before its submission to a journal?

3. What are the policy guidelines in this case which are internationally accepted in academia and research departments.

Kind regards

Hasnain Shah