LibreTexts currently benefits over 100 million students per year and is the most visited OER textbook website in the world. Founded in 2008 as the ChemWiki, chemistry is the major and most used LibreTexts library. Central to its success is the construction and adoption of faculty specific and freely accessible courses using instructor designed "LibreTexts" that substitute for conventional textbooks at both the college and secondary school level. LibreTexts are assembled by incorporating content from an extensive network of existing chemistry and broader STEM materials. For example, Chemistry LibreTexts can include materials from LibreTexts math, physics and biology libraries. The workshop will help anyone interested in building their own textbook or improving existing LibreTexts for their use. Project team members will facilitate this, mentoring small groups in the workshop and offer on-going support for continued adaption and adoption of LibreTexts for individual classes. All participants will receive a printed LibreTexts construction manual at the workshop and a printed copy of their textbook after completion and being made available on the LibreTexts site.