Update merge_field using PATCH method

[ganeshthandapani]

I have 5 merge fields in the account market as required and assigned to contacts. Need to update two of the merge field using the PATCH method. But it returns with an error code to update all required merge field value. My use case is to update only two of my fields. Any ideas.

{
"type": "http://developer.mailchimp.com/documentation/mailchimp/guides/error-glossary/",
"title": "Invalid Resource",
"status": 400,
"detail": "Your merge fields were invalid.",
"instance": "4e565gac-a62f-4813-88b9-aca06dc96884",
"errors": [
{
"field": "MMERGE4",
"message": "Please enter a value"
},
{
"field": "MMERGE5",
"message": "Please enter a value"
}
]
}