Update xml based off datatype

I need to update a value in my xml datatype column, currently I am able to pull specific values using Select AllUserData.tp_ColumnSet.value('nvarchar13[1] ', 'varchar(max)') AS AssetId... My data in the column looks like this, because this is from Sharepoint and I cannot modify the xml format in any way. 0 1995 Ford White Van 123456789 1234 623 Company Dept Section User I have tried to piece together a statement from other questions much like the example with no success and no working where clause as shown below. `update AllUserData set tp_ColumnSet.Modify('replace value of (nvarchar1)[1] with "1996"') where AllUserData.tp_ColumnSet.value('nvarchar13[1] ', 'varchar(max)') = 623` How can I modify the the "Year" by designating what AssetID it is with a where clause?