After the legislative branch votes to release the memo, it would immediately be given to President Trump (executive branch) for his review and approval of public release If the executive branch (POTUS Trump) approves, the material is immediately made available.
However, if the executive branch doesnt approve, then after 5 days, the House of Representatives can vote to override the executive; and, if a majority of the house approve, they can release it despite the executive branch denial. This latter approach is extremely unlikely, because POTUS Trump wants the memo released. (Im just sharing a process example)