The phrase "have disposal" means to have the ability or opportunity to use or access something. There are many synonyms that can be used in its place, some of which include "have access to," "have at one's fingertips," "have use of," "possess," and "have available." Other synonyms for this phrase include "be in possession of," "have control over," "have command of," and "have jurisdiction over." These different word choices can help to add variety and clarity to your writing, while still conveying the intended meaning that you have the ability or opportunity to use or access something.