As far as I know there are no 2 hours demo licenses. A demo license is for 1 calendar month, i.e. expires at the end of the month when it was obtained.
Wonderware is now owned by Aveva and the licensing model has been changing over last couple years, but the last time I checked (1 year ago) it was still possible to obtain a 1 month demo license as a file, and activate it using Aveva License Manager (formerly Schneider Electric License Manager) installed locally.
I think to get a demo license you'll need to register with Aveva support center https://softwaresupportsp.aveva.com/ I'm not sure though about legality of using a demo license for making changes to an application used commercially... you'd need to read their T&Cs.