Partially purge data from a text field

[Dan_Stevens_]

We have a history field used to store web page activity, which is then displayed in our real-time alerts:

It’s a text field (not string) and looks like this in the Marketo:

Even though this is a text field, over time, this may reach its limit by active, known users on our website.  Any thoughts on how to go about partially purging old data – let’s say ‘older than 6 months’ – while leaving the rest of the data intact?

[SanfordWhiteman]

Only via webhook scripting engine, Dan.

Parse as array of date + value pairs, filter, re-join as string, return string.