I originally was going to do the voucher payment plan but have decided to just pay in full. How do I correct this or does it matter. Can I just send in the payment?

Find where to send balance due payments. You can mail the payment, with tracking, no signature to the IRS or you can pay online at Payments.

Other ways you can pay

• Same-day wire — Bank fees may apply
• Check or money order — Through U.S. mail
• Cash — Through a retail partner and other methods

2 responses:

1) if you are talking about where to mail your voucher and check it depends on what state you live in. 

https://www.irs.gov/filing/where-to-file-addresses-for-taxpayers-and-tax-professionals-filing-form-1040-es

2) you might consider continuing to pay quarterly just in case your financial situation changes through the year.  ( My personal opinion and does not necessarily reflect the view of the IRS )