Replace field with commas with field without commas

Hey guys,

I have the following text:

1,2,3,4,5,6,'NULL','when',NULL,1,2,0,'NULL'
1,2,3,4,5,6,'NULL','what','NULL',1,2,0,1

I need the same text with the word NULL without commas
u know something like this:

1,2,3,4,5,6,NULL,'when',NULL,1,2,0,NULL
1,2,3,4,5,6,NULL,'what','NULL',1,2,0,1

thanxs in advance

Try this:

 sed "s/'NULL'/NULL/g" infile