System.Management.Automation.RuntimeException when converting from System.Diagnostics.Eventing.Reader.EventLogRecord to XML

Question

I'm encountering the same issue as mentioned at https://serverfault.com/questions/743515/my-event-log-has-corrupted-dacl-write-attributes-in-4656-file-audit-events/852636#852636 where there are some invalid characters in the event logs and therefore using .ToXML() fails with the exception:

System.Management.Automation.RuntimeException Cannot convert value "http://schemas.microsoft.com/win/2004/08/events/event'>

irrelevant data omitted

<Data Name='AccessReason'>%%1538:   %%1804
    %%1541: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4416: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4417: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4418: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4419: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4420: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4423: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-1513010315-1120)
    %%4424: %%1801  D:(A;ID;FA;;;S-1-5-21-4261485934-2742084322-151301031亖퍲翾</Data>

to type "System.Xml.XmlDocument". Error: "'', hexadecimal value 0x04, is an invalid character. Line 19, position 117."

How could I strip the invalid characters out? I'm thinking the following might be the process:

1. converting to string (ToString() doesn't seem to work, when outputting via Write-Host it simply outputs the name of the object type)
2. removing the invalid XML characters using .replace and regex
3. convert back/serialize to System.Diagnostics.Eventing.Reader.EventLogRecord object (somehow?)
4. convert to XML (with .ToXML())

How would I achieve steps 1 and 3 of this process?