How to move attachments from 1 ServiceNow instance to another ServiceNow instance?

[Suggy]

We have two ServiceNow instances 'A' and 'B'.

We need to migrate all the Contracts from A to B (there are around 5000 Contracts). As both the instances have few custom fields, we have done field to field mapping and moved the Contract data from 'A' to 'B' using import set.

Now how to move the attachements from 'A' to 'B'? (sys_id's of contracts are different in both instances right, so I believe there is no straight way to move across instances). Is there a solution?

Note - This is a one time data migration activity that we need to do.

[VijayPillai]

@Suggy  Did you find any solution? I have a similar requirement.

[Suggy]

@VijayPillai Instead of import sets, we used XMLs - exported and imported. Attachments are also covered with XML.