You can clip or pinch the leaves away from the stems. Use a salad spinner to do the job done more effectively. If you don't have one, washing the leaves in a bowl of water and using paper towels to dry them will work too.  It should be big enough to hold the basil leaves. Be very vigilant to make sure you don't blanch them for longer than this. Move the pot to a different burner so it cools off as quickly as possible. Do this as quickly as you can so that the basil stops cooking. This is the part that takes the longest, so be patient. Just use your hands to individually lay out each leaf and then use a paper towel to pat them dry. You can let the leaves dry for 5-10 minutes if you like. Lay them out individually so they don't touch each other too much. You may find that you have to use two pans lined with cookie sheets. Place the cookie sheets with the leaves in the freezer and wait until the leaves are fully frozen. Then, remove them from the freezer. You can use a zip-lock bag, Tupperware, an empty milk carton, or another container that you can seal easily.

How would you rephrase that briefly using Indonesian?
Pisahkan semua daun dengan batangnya. Rendam daun-daun kemangi di dalam air dingin. Masukkan es batu secukupnya ke dalam mangkuk yang berisi air dingin  Didihkanlah sepanci air. Celupkanlah daun-daun kemangi tersebut ke dalam air yang mendidih selama 5-10 detik. Pindahkan daun-daun kemangi ke dalam air es dengan penyaring. Letakkan daun-daun di atas handur kertas. Letakkan daun kemangi di atas nampan pemanggang kue atau piring. Bekukan daun kemangi. Pindahkan daun kemangi ke dalam wadah penyimpanan.