You need a screw driver, a putty knife, and new ram

Flip the mini over. Insert the blade of the putty knife between the plastic and metal housing on the computer. It's going to be a tight fit.

Pull down on the putty knife to release the clips holding the case together. Work your way slowly around the entire computer.

This is what it will look like when you are ready to move on to the next steps.

At the back of the computer you should be able to see a gap between the housings that is similar to this.

Flip the mini back over. Remove the outer housing and set it aside.

Proof that we are working with a 2009 model Mac mini

Highlighted are 3 antennas that need to be disconnected before we can move on.

The smaller antenna, on the left side can be removed by pulling straight up with gentle pressure

After removing the smaller antennas, remove the springs on the posts under them.

Detach the tape that holds down the wire to the second antenna.

The larger antenna on the right side is attached by 2 clips, they are highlighted in this photo.

Release the antenna by gently squeezing the posts together. Remove the antenna and the spring.

After the antennas have been disconnected, we need to remove the screws holding the drive assembly to the base. The screw locations are highlighted here.

The screw on the lower left side is easy to find and remove.

The screw on the upper left side is a bit harder to find and remove.

This is where the next screw is. Make sure not to lose them after they are removed.

The last screw is the hardest to get to. It's a bit larger then the others. Remember where is went.

Next we have to find and detach the ribbon cable. It's highlighted in this photo.

I stuck the corner of the putty knife behind the connector and gently twisted until the connection popped off.

The ribbon cable should disconnect with out much force.

You can now gently lift the drive assembly off of the base. Set the drive assembly to the side, the RAM is in the base.

The RAM is held in place by 2 retention clips. One of them is highlighted here.

Gently press outward on both clips at the same time to free the RAM.

The RAM will pop up at an angle. Remove the RAM by pulling it straight out of its slot.

The RAM has been removed. This is a factory 1GB RAM module.

We are going to be installing 2 x 2GB RAM modules.

Put the new RAM in the slot we just took the old RAM out of.

Press down on the RAM with 2 finger applying even pressure. The retention clips should catch the RAM.

The retention clips will hold the RAM in place. Congratulations, you just installed some RAM!

Install the second RAM module into the second slot.

Press down on the RAM until the clips catch.

This is what the RAM will look like once installed.

Place the drive assembly back onto the base. Make sure that the antenna wires aren't getting pinched.

Screw the drive assembly back onto the base. The screw locations are highlighted.

Re-Attach the ribbon cable.

Apply gently pressure on the connector until it snaps into place.

Replace the antenna springs.

Replace the antena and press down on it until snaps into place. Re-attach the tape on the wire to the drive assembly.

Replace the next antenna. Press down on it until is locks into place.

Attach the last antenna by gently squeezing together the 2 posts under it (highlighted here), pressing down on the antenna and releasing the posts.

Replace the top cover.

Gently press down with even pressure until the clips grab the top cover and lock into place.