Brake fluid leak

[dogbreath100]

Hi , I started the van this morning to notice a spongy brake pedal .
The leak was coming from the brake light switch which I replaced a few weeks back . 
I tightened the switch and refilled the fluid reservoir and the brake pedal is still spongy .
Where would be the best place to start bleeding from . Thank you .

[R0B]

Nearside rear. Offside rear. Nearside front. Offside front. In that order.

[dogbreath100]

Thanks for that , I’ll give it a go the weekend  .