Tiger cat, front caster grease cap question

I'm wanting to grease the caster spindle bearings on my Tiger Cat and I see Scag recommends a tool to replace the caps.

Before I remove I I'm wondering if that's actually necessary to replace the caps?

Other option is drilling small hole in the cap so I can see when enough grease is added. But that would make me worry about contaminating the bearings eventually. Though I suppose some silicone would prevent.

No it’s not necessary you can do without it. Sometimes if you put too much grease in them it will start to push the caps up. Drill holes I wouldn’t it will allow water and other stuff in as you said.