Process to Upgrade Zookeeper from 2.7.0 to 3.4.1

Hello Guys,

Iam new in this space, I was going through the documentation of Upgrading
Kafka brokers to 3.4 from any previous version with Zookeeper mode , but I
couldn't find any Upgrade process for Zookeeper.

Iam using Zookeeper provided by Kafka binary in this case 2.7.0 and not
installed zk externally.

So what's the process of Upgrading Zookeeper? And should I upgrade
Zookeeper first or 3 Kafka brokers?

Note - I have single Zookeeper and 3 Kafka brokers at this point.

Regards,
Gaurav