Here's a step-by-step copy-paste tutorial: Requirements:

• related Site Account has ssh enabled
• Scope cp.config ssh:user_daemons is enabled

# Create a new Redis instance for benchmark.test named "wp-test" listening on /tmp/redis.sock
cpcmd -d benchmark.test redis:create wp-test '[unixsocket:/var/www/redis.sock,unixsocketperm:0660]'

# Switch to benchmark.test account to configure plugin
su benchmark.test
cd /var/www/html

# Install Redis object cache plugin
wp-cli plugin install --activate redis-cache

# Define Redis path
wp-cli config set WP_REDIS_SCHEME unix
wp-cli config set WP_REDIS_PATH /var/www/redis.sock

# Enable Redis plugin
wp-cli redis enable
# Verify it is running
wp-cli redis status

Should you need to delete an existing Redis instance, you can go with:

cpcmd -d benchmark.test redis:delete wp-test

Optionally have some fun:

# Define key for site
wp-cli config set WP_CACHE_KEY_SALT benchmarktest

# Enable igbinary serializer
wp-cli config set WP_REDIS_IGBINARY true --raw

# Disable plugin banners
wp-cli config set WP_REDIS_DISABLE_BANNERS true --raw

Looking for installing igbinary PECL module? Learn how here