i have 2 of this machines, and taking out the printhead in RJ900X its pretty easy, there are no screws holding it except for all that plastic things on top of it.
As i can se you've already taken the weight away you must put that again for future working if not the carriage is very light and will make noises.
1°: Take out the front cover. for working more confortably.
2°: unscrew all plastic sourrounding on top (you will see that the plastic cover is made by 2 separate parts) left and right, unscrew them and take them out. You will have 2 or screws on top and 2 on the sides of the head carraige.
3°: Take out the screws securing the silver weight. (you will take screws of all plastic stuff on top of the head).
4°: The most difficult part is taking out the clip latches as you marked in the picture. You have to make a little strengh with a flat screwdriver and taking out 1 by 1 until they are all out. (the 1st time i've done this i was afraid, actually broke 1 from one of my machines, but the good thing is that they arent necesary at all after you take them out... i'll send picture of my machines for you to see.)
5°: Take out dampers and put them aside, You will have the base of the cover(latches part) that is beeing hold only by the screws taken out in the step 3. This is a necessary part so try not breaking it. It holds with only 2 pins and holes behind it and the 2 front screws(silver weight screws)
6° Taking out the printhead its not hard but must be very carefull, printhead is only tighten with a plank/lever making pressure (you will see it right in fron of you) and a very tiny screw on the right that makes a little pressure and aligns it. You can take the flat cables now or after this.
Unscrew the screw (?) a little bit, and then hold the metal plank or lever tight to the metal side of the carriage, and then pull the printhead upwards. (First time i've taken out this printehead i've made a bad scratch for not know of this metalplank/lever.
7° Printhead is out take out the flat cables.
For installing make the steps backwards.
Insert flat cables -> Hold tight the tiny metalplank/lever to the carriage, and put the printhead back inside of it -> tightend the right screw with your hand. (Make sure the printhead is horizontal and not inclined to a side or back). The best way to avoid inclination is to put the back of the printhead first and then the front (the metal plank side)
Let go plank and the printhead will be in its place.
After this: Put the plastic base taken out in step n°5 and you will see 2 tiny holes on the back of the carriage like in the plastic part. Hold tight making a little streght down and backwards and put the screws taken out in step n°3 (silver weight). Once you put this both screws the platic wil barely move. After this put the 8 dampers in order. and finally unscrew both front screws (step N° 3) and put the silver weight again back on.
After all that re-assemble the top of the carraige if you want to(i'll suggest to) because of flat cables and ink tubes.
Please ask anyquestions if you want sorry for my english did my best =/
Hope it helps.
