Exit strategy advice.

I have identified a number of price points at which I wish to take profit for each of my crypto coins.

For example, if XRP hits $1.9 then I would sell (say) 10% of my coins.

I was thinking of doing this manually, but on second thoughts it might be better to set up an automatic payment on an exchange. (I prefer Kraken).

My latest thinking is that I would like to set up an automatic trade to sell my XRP and set a limit order (if for example it falls to $1.80) and either set a trailing stop, or periodically manually adjust the stop loss. In this way I can take advantage of further rises in the price but still sell if there is a sudden dip.

I had a look at Kraken, but could not see how to set this up (I can't seem to automate sell XRP orders).

How can I do this?