Yes, you can change your postal vote application to a regular vote. If you no longer wish to vote by post, you can simply go to your designated polling station on election day and vote in person. If your postal vote application is cancelled (for example, if you don't renew it), you'll still be able to vote at the polling station as usual.
If you have any further questions about voting or need to check your registration, you can find more information on the Bolton Council voting page.