On the left-hand side of the screen in the navigation bar under Events, select Chassis. This will take you here:
Under the table titled Chassis, scroll to find the name of the chassis you wish to edit. Then, click on the name of the chassis.
This will bring you to a new window that looks like this:
At the top right of the screen, select the button with a pencil icon titled Edit within the box with the chassis name. The box will look like this:
Use the text box at the top of the screen to edit the chassis name.
Directly underneath the name is a larger text box. Use this to enter a description for the chassis.
Use the text box titled Size to enter the size of the chassis. Then, use the text box directly underneath, titled Tonnage, to enter the weight of the chassis.
Use the dropdown menu titled Maximum Riders to select the maximum number of riders the chassis can hold.
Lastly, select whether or not the chassis is active by using the dropdown menu titled Active.
When you have finished editing the chassis details, select the button at the bottom of the window titled Update.
These are sample names.