Manually adjust donated amount

I want to have a campaign allowing people to pay online or drop money in a collection box at our facility. What is the best way to add the money dropped off in person to the campaign total so the percentage of goal is correct? I tried to modify donated amount in admin but it is read only.

Any suggestions?

I'm also looking for a way to add money donated outside of the component to the Progress and Thermometer. We had to start the campaign ahead of the completion of the page, so we have some donations made already.

There are too many to input manually into the Donors list on the back end, and I don't want to make a single large fictitious donation as that would end up on the Top Donors list.

I'm okay with modifying MySQL data if that's what it takes.