Go to Fundraising >Campaigns >Campaign Pages. To locate the page that you would like to edit you type the name of the page in the "search" field or you can sort the Campaign Page list by name.

After you locate the page that you want to edit click the "Edit Page" button.

If you want to edit General Information such as name this info can be located on Step 1.

Design elements such as campaign page copy and colors can be found on Step 2.

If you have enabled "Fundraising" Step 3 is a preview of the Fundraiser page. 

On "Step 4" you can edit information displayed on the "Thank You" page. This info includes Thank You graphic and message.

At any time after making an edit simply click the "Save Draft" or "Finish" button.