I have downloaded a few apk's from APKmirror
removed skype from my Nexus 5x
adb install -r -d com.skype.raider_188.8.131.52-119668850_minAPI15\(armeabi-v7a\)\(nodpi\)_apkmirror.com.apk
5486 KB/s (37425319 bytes in 6.661s)
Is there any way to downgrade without error? I do not like what Microsoft did to skype at all.