
happykj |
"Construct Modifications
Standard constructs can be modified to enhance their base abilities, alter their appearance or function, or perform a variety of tasks beyond the intentions of their basic designs. Performing a modification provides a construct’s creator with a simple way to create a unique construct. A modification can only be performed while the construct is inanimate or nonfunctioning. Performing modifications on one’s own construct requires the Craft Construct feat, and the creator must pay any additional crafting requirements and/or costs associated with the modification. Completing a modification requires 1 day per 1,000 gp of the modification’s base price (minimum 1 day)."
Not with my laptop now, so i copy this from d20pf. The paragraph does mention "construct's creator", and never talk about non-creator doing modification for others,
so i guess the answer is No, at least the rule didnt say yes for it. Also I dont think the Wyrwood will be comfortable to be nonfunctioning and let other people doing modification on him

Azothath |
Wyrwood race description is what PCs start with.
There's no construct crafting options listed with prices as that's what PCs craft or create.
If your Home Game is starting at higher level and PCs have cash to spend then self improvement is an option by having a suitable NPC perform the work.
Construct modifications

Mysterious Stranger |

Looking at the alternative racial traits for Wyrwood in Hero Lab I am seeing modifications from the construct handbook. Self Repair (Fast Healing) is one of the listed modifications. So, while Hero Lab is not an official source, they do have a relationship with Paizo and usually check with them about the rules. This is still going to be a GM call. Personally, if I am letting the other players have items made, I would not have a problem with allowing this.
The Fast healing does have some limits that make it less troublesome. The healing has to be activated as a swift action and only works for a number of rounds equal to half the characters HD (minimum of 1).