Follow this link:https://www.ptc.com/appserver/lm/rsl/reconfig.jsp. It will being up the web tool for moving a license. I usually have a new one within an hour.
Are you on Windows ?
FlexLm looks in the registry for the first Network Card in HKLM\Software\Microsoft\Windows NT\CurrentVersion\NetworkCards and uses its MAC adress for licensing. The order is alpha numeric which means 10 is before 2. You can reorder them by renaming the folders but set a breakpoint first so you can roll back to the old state.
If you are using removable cards the order may change as the driver is loaded only if the card is connected to a network. So google for MediaSense and create a key which always loads the driver and therefore does not change the registry order.
You can get a new license file or carry the old network card over to the new server.
This is for XP, Windows 7 may be different but I doubt it.
Editing the license file will corrupt it.
Yes I am using windows. We are upgrading the server it is hosted on, but in the meantime are going to be completely formatting the drives and rebuilding it from scratch, so while we are doing that we just want to move the license server over to a temp location until the original is back online. I am working on getting a new license file from PTC now to move it that way.