Compaq 486 Maintenance And Service Manual page 66

5. Carefully pull the processor board out of the slot (Figure 5-10).
To replace the processor board, reverse the steps in the above illustration.
System ROM
To remove the system ROM from the processor board, complete the following
steps:
1. Remove the rear panel (Section 5.6).
2. Remove the options cover (Section 5.7).
3. Remove the video board (Section 5.8).
4. Remove the processor board.
5. Locate the system ROM on the processor board (Figure 5-11).