Change Result Recording after digital signature done

Dear Experts ,

I have  a requirement from the Business .

1. The User has done one result recording for one char eg -- Assay Value -- 98 ,
2. After that Digital signature is kept on Result Recording stage ,
3. Later the user realized that , the Assay Value needs to be changed from 98 to 102 .(Char value to be changed)
4. Since once Digital Signature has been done on Result Recording , The values cannot be changed/edited .
5. Is their any way to change the char values even after digital signature has been done in Result Recording .

Regard's

Tallha