IOW is an abbreviation for "in other words". Though many people use it in conversation and writing, it can be helpful to switch things up and use synonyms for IOW that provide a similar meaning. Phrases like "put another way", "to clarify", "in essence", and "to rephrase" can all be used in place of IOW to deliver the same message. Alternatively, you could use an abbreviated phrase like "TLDR" (too long didn't read) or "ELI5" (explain like I'm five) to summarize or restate your point. Varying your language and using different synonyms will help to keep your writing sounding fresh and interesting.