免 (to avoid/exempt) + the resultative complement 掉 ('off, away, do away with'). 掉 attaches to many verbs to mean 'finish off / get rid of': 吃掉 (eat up), 扔掉 (throw away), 关掉 (turn off). 免掉 = 'avoid-away' = remove from the picture.
usage
Less formal than 取消 (cancel) or 省略 (omit) — 免掉 has a casual, practical 'just skip it' feel. Common with 麻烦 (hassle), 步骤 (step), 手续 (procedure), 费用 (fee).
