How to downgrade metasploit on kali rolling?

I always be neat with any installations on kali-rolling paying attention to it's unstableness and prefer to follow official instructions in this question. But today I face the problem with downgrading metasploit framework from 6 to 5. Can you answer me next questions I dealing with:

1. Is it possible to downgrade only metasploit repository, but NOT the whole kali build?

2. If previous answer is "yes" , can I keep both msf versions at the same time on single OS?

3. What the safest way to downgrade?

Any instructions or quick guides would be appropriate.