Remove The Heat Sink - Lenovo IdeaPad 5 Hardware Maintenance Manual

"Remove the solid-state drive bracket" on page 49
Step 1. Disconnect the I/O board cable from the system board and then remove four screws.
Figure 42. Disconnect I/O board cable and remove four screws
Screw specifications
M2.5 x L5
M2 x L3
Step 2. Open the hinge and then remove the I/O board with cable.
Figure 43. Remove the I/O board with cable
Go to https://support.lenovo.com/partslookup
replacement part:
I/O board with cable

Remove the heat sink

Make sure the following FRUs (or CRUs) have been removed.
"Remove the lower case" on page 46
Step 1. Disconnect the battery pack cable from the system board.
Number of screws
2
2
to look up the Lenovo part numbers of the following
.
Chapter 4 Removing a FRU or CRU
51