Before agreeing to rujuk, what should I ask my husband to change first?

Ask for change in the things that caused the separation, and make sure it is clear and visible. For example, if the main cause was maintenance (nafkah), ask for a fixed maintenance schedule. If the cause was harsh words, ask him to attend anger-management counselling. If the cause was family interference, an agreement on where you live and limits on interference may be needed. Write the agreement down together so both of you remember what was promised. Avoid a list of demands so long that it sounds like a punishment; choose the two or three most important things. Also give him room to say what he hopes for from you, because healing is a joint effort. See rights of husband and wife.