Hi,
For example, I backed up the private keys of my addresses in the electrum wallet. How can I install multibit hd wallet from again using these private keys?
AFAIK, you can't import anything into Multibit HD and they don't adopt the same seed deviation method as Electrum. Hence, you need to send the coins to a wallet created by Multibit HD's seed.
You can import into Multibit Classic though[1]. Can go through more in depth for you, if you need.
[1]
https://multibit.org/help/v0.5/help_importingPrivateKeys.htmlI understand that we can not use private keys in other wallets. The Multibit HD wallet does not have a private key insert or eject menu. I think this is the only feature in the classic version. In the new version they removed the use of private keys.
Then it makes more sense to make the backup process with seed words. Already we can only use the private key in the corresponding wallet. Rather than backing up private keys, backing up seed words is simpler.