Welcome to PilotsNPaws. What I usually do is just leave the posting as is. I usually don't get replies to the posting itself anyway. I would start sending e-mails to the pilots along the first part of the trip and just put in your e-mails that you have a pilot for the Pittsburgh to CT leg and still need the first leg from Topeka to Pittsburgh. Once you have your first message composed, copy and paste to all the other e-mails to save time. Also, in the subject line of your e-mails, be sure to put PilotsNPaws Request-Topeka, KS to Pittsburgh, PA. Some pilots get so many e-mails that they don't open it unless they know it is a PNP request.
Once you have the trip "spoken for", go back to your origianl message and click on "Edit" in red on the top right of your message and put "FILLED" in the subject line. Then after the trip is complete, use the same process to write "COMPLETED" or "DONE" in the subject line.
Let us know if you need further help.