Without reinstalling and moving the gamefiles how to change aoe path in voobly to an other instance installed on the pc?

ty

This is currently unsupported. We recommend keeping the original installation paths.
https://support.voobly.com/display/vkb/KB1053+Clean+installation+of+Voobly+client
https://support.voobly.com/display/vkb/KB1054+Clean+installation+of+Aoe2HD+with+compatibility+patch
https://support.voobly.com/display/vkb/KB1019+Clean+installation+of+Age+of+Empires+II+with+the+latest+patches

There exist third party tools in order to achieve this, keep in mind though, that you use them at your own risk + we do not offer support for these tools.

will at least reinstalling solve this problem? cuz Program Files such a slow directory

It is not a good idea to have multiple custom installations of the game. I would suggest uninstalling all of them and following the clean install guide as mentioned above, to install the game at your default location (program files).

From your last comment it seems you are worried about game lag but rest assured, installing the game in program files will not be a cause of it.