Change Primary shards number

Hello! i use elasticsearch 7.4.0 and i want to change the primary shards number on existing indices
how can i do this? i want to increase some primary shards, and decrease

See https://www.elastic.co/guide/en/elasticsearch/reference/7.9/indices-split-index.html and https://www.elastic.co/guide/en/elasticsearch/reference/7.9/indices-shrink-index.html

thank you my friend! it works brilliant!