Hi there again.
Thank you guys for very helpful information.

I am continuing my work with a prospective clinical study for my project.
You taught me how to add text to the existing records. Would you mind to help
me with several tips on deleting small parts existing text in the column?

Ex:
ID Patient Tissue type Code
10 Snow, John Plasma 10SJ-P
11 George, Roy T-cells 11GR-T

I want to delete "P" and "T" for all samples in the Code column. The
expecting result should look like this:

Ex:
ID Patient Tissue type Code
10 Snow, John Plasma 10SJ
11 George, Roy T-cells 11GR

Thanks a lot!!!
Daniel