Change the format of two columns and convert the file into txt file

Help
1

i have a xlsx file which has dupliacted column names. I want to change the format of 3rd and 4th column to “yyyy/mm/dd” and convert it into txt file. i have attached the file below
Salary Payroll PE 08 17 2019 JV_Aug2019.xlsx (1.2 MB)

2

@Palaniyappan will appreciate your help

3

But i dont find any value in the 3rd and 4th column
and
would you like to change the datatable to a text file
@shishirshetty2701

4

first remove duplicate columns.

Thanks,
Paro

5

@Palaniyappan C2 and D2 has value. please check

6

but i have from 239
image

Cheers @shishirshetty2701

7

@Palaniyappan please scroll up. Iam able to get the remaning rows.