There are five completely unnecessary steps in this guide all centered around removing the PSU and the part under it that don't need to be done in order to remove the motherboard/heatsink. You can cut out steps 38, 39, 41, 42 and 43 on step 40 you only need to remove the three 35mm screws to complete the step. As long as you complete the rest of the guide the top comes away without issue.