Make 2 back ups of each 19PE and 22PE Data Folder. You can never have enough backups and I would place each set in 2 different locations.
Open Trainz 22PE and put in the path to the 19PE Data folder you were using. Start and make 22PE now sees your 19PE Data and all is well. Double check everything twice, if needed.
If something doesn't go right you have the original folder and 2 backups to fall back on.
***I would caution you about trying to open Trainz 19PE afterwords, as this will surely mess up your database and probably make it unrecoverable.***
Matter of fact, since you want to use only 22PE with the 19PE data folder you have now, you might think about deleting Trainz 19PE from your computer entirely BUT only once you have 22PE up and running with all your old data intact. I cannot say this enough, if you open and try to use 19PE once you put your Data folder into 22PE and have it running they will each point to the same data folder and your database may become recoverable.
Yes, you can change Data Folder paths/names in both Trainz Settings and Finder and both 19PE and 22PE can work. This is why I asked if you wanted separate installs or just 19PE data into just 22PE. The info above is not for making both work together.
Hope I didn't confuse, its a really simple process, but I would never like it if I didn't point out certain things and anyone lost everything, either Trainz related or even their computer.