File with double quotes

Shell Programming and Scripting
1

I have one file a.txt as below.
a.txt

"aaas","111111","ewwee32e","deee333",
"aaas","111111","ewwee32e","deee333",
"aaas","111111","ewwee32e","deee333",
"aaas","111111","ewwee32e","deee333",

I want to write a script to process a.txt and want the output as below in different file as below -
b.txt

aaas,111111,ewwee32e,deee333,
aaas,111111,ewwee32e,deee333,
aaas,111111,ewwee32e,deee333,
aaas,111111,ewwee32e,deee333,

Kindly somebody advise me.
TIA

2 
 
sed 's/"//g' a.txt > b.txt
3 
tr -d '"' <a.txt> b.txt

Note: ('"') = (single quote then double then single)