1. Remove panel around gear lever. For manual it's only held by clips, no screws to remove, don't know about CVT.

2. Remove the cupholders and the panel as shown in the pic below. Once the visible screws are removed, the panel is held by clips and you have to pull very hard to loosen it. Remember to unplug the 12v power socket connector.

3. Screws holding down the HU and the storage compartment should be exposed, the two will come out together and you can then separate the HU from the compartment.

4. Most likely the plug for the stock HU will not fit your new HU, you either need an adapter, or in my case, cut the wires from the stock HU and attach to new HU.

Btw this is the stock HU socket, see if it matches the one of your new HU.