Update release instructions

MAINTAINER.md

@@ -1,8 +1,7 @@
 
 ## How to release a version
 
-- create & push a release branch `release/vA.B.C` -> the prepare_release action will automatically create the PR to merge this release into master.
-- Update version in podfile & run pod install to update podfile
-- update changelog
+- create release branch `release/vA.B.C`
+- run `bundle exec fastlane prepare_release`, this will update the version number in the podspec based on the release branch.
 - merge PR -> the CI action will trigger a pod release and tag the commit
 - once the PR is merged, merge the branch `release/vA.B.C` into master