Please be specific as to what strings you want to change. Most strings are found within your CBSubs language files below.

/components/com_comprofiler/plugin/language/cbpaidsubscriptions-en-gb/language.php

If the above doesn't exist then you need to install it from the CBSubs package.

Some strings can also be found in CBSubs > Settings > Display.

1)there is a colon in front of Yearly Paid Electronic Access.

Not familiar with the colon display or where it's coming from, but that text is typically the payment item text, which you can configure within your plans on the Pricing tab under "Payment invoice item text".

2)I want the subtotal to just say $260.00 (minus the ",then $260.00"

Believe that is the below language string found in the CBSubs language file as provided earlier.

3)I want the the Prorated Initial Registration to say just "-132.49" (minus the ",then $0.00"

Probably the same string above.

4) and I want to change "approve" to "approved".

That's the below language string.

Also I was looking for this
/components/com_comprofiler/plugin/language/cbpaidsubscriptions-en-gb/language.php but I could not find it. Are you certain this url is correct?

Yes, that's correct. Please see my previous reply as stated if it does not exist then you did not install the English language plugin included with CBSubs and will need to do so.