you can chance one position at a time. ConeColor ink is encapsulated pigment in a formulation very similar to Epson encapsulated pigment. No need to flush. Let the ConeColor ink simply displace whatever leftover Epson ink remains!
The process is for refillable cartridges. Putting a syringe into the ink port of the Original Cart will break an anti-refill mechanism and render it useless.
I still have Epson ink in my 4900, but I am running out of black. Is your ink & Epson's compatible? Do not have $800-$1100 to replace all the cartridges. Thanks...
These refillable cartridges cant fit properly in an Epson 4900 save yourself the headache before you break parts in your printer, notice she never showed the cartridge being inserted into the printer because it doesn't work!