Below you will find a couple video links.
One is how to install a package in general.
The other is how to install a package during rainy weather.
Installing Package Bees in a Langstroth Hive video:
Hiving Bees in Rain and Sleet
Spring buildup time!
Monitor overwintered hives for swarming signals
Consider reversing or splitting strong hives
Check mite levels in overwintered hives
Feed new packages 1:1 syrup