Replacing Circuit Board with a switch?

Hi!! I'm new to this website, so I'm sorry if I haven't posted in the right forum.

I'm interested in purchasing the DIY Solar LED Jar Light Kit from Sundance Solar (link below to the product). However, I would rather use an on/off switch than a dusk/dawn circuit board.

Is it possible to tell me if the circuit would still work if I replaced the circuit board with an on/off switch?

Could someone also make a simple circuit diagram for me please?! Really simple if possible, I'm not an expert in circuits, just doing this for a bit of fun!

Thank you for your help!
**broken link removed**

This is a .pdf file showing one schematic of what should be the board. The schematic should look about like this:



Page 9 of the manual reads in part:
"Working from left to right, you can see that there is an outer and an inner circuit leading from the solar cell to the blocking diodes (1N5819) before it gets to the batteries, in order to keep energy in batteries. The outer circuit is for the optional external on/off switch (Switch1), so that the lantern can be manually turned on or off regardless of time of day or battery charge level".

Ron