Is there any way to increase the "OLAP Drill Through number of records to retrieve" in Excel 2013 as it is currently greyed out/ un editable?

Check out this Question/Answer.   

https://social.technet.microsoft.com/Forums/en-US/d1de78a4-f519-4630-b490-321455f20bab/excel-2007-olap-drillthrough-how-to-changeremove-limit-of-1000-rows?forum=sqlanalysisservices

Hi CRC Kiwi:

Im regret to tell you this is a bug in excel 2013, but it works fine in excel 2010.

Thus, if you need to change the maximum number of PowerPivot Drill-through rows in Excel 2013. You can use workaround to solve this problem

1.

Posted by Kwenix on 6/14/2013 at 2:50 AM

take copy of your xlsx file
-- from here you're on your own..
rename xlsx to zip file
open zip file using 7z
locate connections.xml file in 'xl' folder
hit F4 in 7z to edit file
locate rowDrillCount="1000" and change to desired value
upon saving 7z will update file into the zip file
rename zip to xlsx
it works (for me) with 7z (not with file explorer zip extraction) and avoids to return to Excel 2010
If it doesn't work, see step 1 of the procedure for a backup

2.

Posted by Gavin Campbell on 3/5/2013 at 7:43 AM

Using the 2010 version of the workbook and Excel 2010, change the max rows returned property to 1 million. Then open the workbook with Excel 2013.
As before, the properties dialog is disabled, but the setting of 1 million rows persists.

Please reference this connection

https://connect.microsoft.com/SQLServer/feedback/details/780558/powerpivot-drillthrough-limited-to-1000-rows-in-excel-2013

I hope my answer can help you.

Regards