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this is not a simple process, as you need to check the queries of the one that "block" the others as they run long time, and use (block) resources long time.
if you have a reporting on the OLTP database, you might consider to replicate the users database to a reporting database, so you separate the OLTP transactions completely from the reporting queries.
depending on what reporting you have, it could be a daily full backup + restore, or indeed a full transactional replication.