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I use the Editor to upgrade my technology. For example, I activate Infantry division -47, with prereqs.
But when I play, the tech is not applied to the scenario. The tech is added, but my Infantry division stays at v. 36...
In case you didn't notice yet: Don't use the editor, it's broken and can corrupt your saves and game files. Just don't use it ever! All you want to change can be easily changed using notepad, as all the stuff is in plain text files. Read the HoI2Wiki for further instructions: http://www.paradoxian.org/hoi2wiki/index.php/Mods
Now on to your specific question: You got the tech, now you need the unit to upgrade. This has nothing to do with the editor, this is just normal game mechanic. After researching a better tech, you need to assign IC to the upgrades slider in the production menu and wait some weeks. Your unit will start to upgrade to higher models (in your case going from 1936 to 1939, then to 1941, then to 1943 and finally to 1945 infantry). This will take some time, so be patient.
If you want to have the new units, either build them (only takes 3 months, which is about 2-5 minutes max on higher speed settings) or edit the scenario file with notepad, searching for the name of the divisions and changing their model from 1 to 5.
