Correct way to sell off returns

Apologies if this has been asked many times before but I’m reading conflicting information on this.

I have 2 pies and a Crypto ETF in my portfolio. 1 pie is for long term growth and has multiple ETF’s in it. The other pie has a selection of mostly European defence stocks. The Defence pie and Crypto ETF are meant for short term returns which I will then move over to my long term pie.

How do get the returns out of the Defence pie without affecting my Net Deposits? I watched some videos on how to Withdraw and how to export from my pie first before then selling the exported amounts but I dont see the difference between these 2.

Also, if I use the export and sell option, will this money still stay within my S&S ISA and not trigger any tax related event? We’re still talking about small amounts at the moment but hopefully that will change in a few years.

Any simple explanation would be appreciated.