Remove single column mobile no by manually

1. Select the disired column mobile phone no.

2. use the function left (text, 4 letters) and right (text, 4 letters) to sort out the numbers

3. to concentate the left and right number


4. use if (text = lower text) then sort out duplicate, totally use 4 if functions

5. after that use copy and paste function to fix the value.

6. insert a 2nd column of heading, a0001, a0002, a0003...... to create a header so that allow sorting out the duplicate value and delete by comparing manually.