How to downgrade IONIC2 beta to IONIC 1 on Mac?

Hey guy,

I’ve try to install ionic 2 beta but now my customer require develop project with IONIC 1, but now I can’t install IONIC 1 after remove ionic 2 and reinstall ionic with “npm install -g cordova ionic” it always install ionic 2.

Please help me to dowgrade ionic 2 to 1.
I’m use MacOS 10.12 (MacOS Sierra - public review 6)

Thanks & Best regards,