Just Solved my issue. I too wanted to try the Microsoft launcher app but it changed my screens too much and I didn't have time to reset everything.
So I tried to do a simple uninstall however the Uninstall button was not active and the force stop would not work on my android LG stylo 2.
I went into general phone settings>Apps>Microsoft launcher> settings> turned off permissions & then turned off Default setting.
Once I revoked the app's permissions and default setting for the launcher I was able to force stop it and the uninstall button became active. Then I was able to uninstall and choose the home screen I was used to. Now everything is as it was. Thanks goodness!!