How to Extend Portion of Model/Face?

[BRIANBN59M]

Hello, I am looking to extend the portion of this model as per described in the images. I only want those 2 portions to be extended in order to fit a different size fan. But, because I didn't make this model myself, I don't have access to the sketch where I would normally just extend those portions. 

Just to be clear - for the top portion (outlined by the two lines on the top of the model), I want to extend that portion in the Z direction (essentially make that part longer), and for the portion on the right, I want to extend that in the X direction (again, to make it longer). I don't just need that one face (where the lines are drawn) to be extended - I want that whole 'arm" portion of the model to be extended in the Z and X directions, respectively (as shown by the arrows in the pictures)

I have absolutely no idea how to do this and everything I've looked up doesn't seem to work in my case. Can anyone let me know how to go about this/walk me through it? It would be much appreciated. Thank you!

[HughesTooling]

Move set to faces should work and make sure the move type is set to translate. Also turn on history before making any mods. And please don't attach pictures, either paste them from the clipboard of use the Insert Photo option.

Edit, if you're still unable to modify this part, attach your f3d file.

[jhackney1972]

Please attach your file.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section of a forum post to attach it.

[HughesTooling]

Just to make it a bit more clear here's a better view of the 2 faces I selected.

[BRIANBN59M]

I included the Step file below. I think I have to try to learn this for myself because I am trying to make a very specific change - I need the mount to accommodate a different 5015 fan. I just realized that I have to change the file quite a bit to accommodate the new fan. I originally thought I would just have to extend the mounting points. 

I included the pictures below of the two fans - the RLF 35-8/14 N is the one I need to change the model to fit. The model is based on the dimensions of the other image I included below (GDSTime 5015 Fan 24v). 

Is this an easy change to make?

[mango.freund]

I think your colleagues have already answered your question, but are you sure you want to print this part? Yes? I would advise against that because it is too fragile. you will also not be happy if the support structure has to be removed you break the part (my experience of breaking something is very high). shape all passages oval or round. all edges with radii and stiffeners wherever possible. try to position the part in such a way that the layer can avert the fragility. no support structure is the goal.

[mango.freund]

hello @BRIANBN59M there is a similair model for anet8? when i will do it again so i will turning the exit 90 degré