2 new Preternis surgeries allow them to detach and attach their robotic limbs

code/modules/surgery/amputation.dm

@@ -6,6 +6,23 @@
 	possible_locs = list(BODY_ZONE_R_ARM, BODY_ZONE_L_ARM, BODY_ZONE_L_LEG, BODY_ZONE_R_LEG, BODY_ZONE_HEAD)
 	requires_bodypart_type = 0
 
+/datum/surgery/amputation/mechanic
+	name = "Detach mechanical limb"
+	self_operable = TRUE
+	requires_bodypart_type = BODYPART_ROBOTIC
+	possible_locs = list(BODY_ZONE_R_ARM, BODY_ZONE_L_ARM, BODY_ZONE_L_LEG, BODY_ZONE_R_LEG)
+	target_mobtypes = list(/mob/living/carbon/human)
+	lying_required = FALSE
+	steps = list(
+		/datum/surgery_step/mechanic_open,
+		/datum/surgery_step/open_hatch,
+		/datum/surgery_step/mechanic_unwrench,
+		/datum/surgery_step/prepare_electronics,
+		/datum/surgery_step/sever_limb/mechanic
+		)
+
+/datum/surgery/amputation/mechanic/can_start(mob/user, mob/living/carbon/target)
+	return ispreternis(target)
 
 /datum/surgery_step/sever_limb
 	name = "sever limb"
@@ -27,3 +44,23 @@
 		target_limb.drop_limb()
 
 	return 1
+
+/datum/surgery_step/sever_limb/mechanic
+	name = "uninstall limb"
+	accept_hand = TRUE
+
+/datum/surgery_step/sever_limb/mechanic/preop(mob/user, mob/living/carbon/target, target_zone, obj/item/tool, datum/surgery/surgery)
+	display_results(user, target, "<span class='notice'>You begin to detach [target]'s [parse_zone(target_zone)]...</span>",
+		"[user] begins to detach [target]'s [parse_zone(target_zone)]!",
+		"[user] begins to detach [target]'s [parse_zone(target_zone)]!")
+
+/datum/surgery_step/sever_limb/mechanic/success(mob/user, mob/living/carbon/target, target_zone, obj/item/tool, datum/surgery/surgery)
+	var/mob/living/carbon/human/L = target
+	display_results(user, target, "<span class='notice'>You detached [L]'s [parse_zone(target_zone)].</span>",
+		"[user] detached [L]'s [parse_zone(target_zone)]!",
+		"[user] detached [L]'s [parse_zone(target_zone)]!")
+	if(surgery.operated_bodypart)
+		var/obj/item/bodypart/target_limb = surgery.operated_bodypart
+		target_limb.drop_limb()
+
+	return 1

code/modules/surgery/prosthetic_replacement.dm

@@ -13,7 +13,23 @@
 	if(!C.get_bodypart(user.zone_selected)) //can only start if limb is missing
 		return 1
 
+/datum/surgery/prosthetic_replacement/mechanic_limb
+	name = "Attach mechanical limb"
+	self_operable = TRUE
+	possible_locs = list(BODY_ZONE_R_ARM, BODY_ZONE_L_ARM, BODY_ZONE_L_LEG, BODY_ZONE_R_LEG)
+	target_mobtypes = list(/mob/living/carbon/human)
+	lying_required = FALSE
+	steps = list(
+		/datum/surgery_step/prepare_electronics,
+		/datum/surgery_step/add_prosthetic
+		)
 
+/datum/surgery/prosthetic_replacement/mechanic_limb/can_start(mob/user, mob/living/carbon/target)
+	if(!ispreternis(target))
+		return FALSE
+
+	var/mob/living/carbon/C = target
+	return !C.get_bodypart(user.zone_selected) //can only start if limb is missing
 
 /datum/surgery_step/add_prosthetic
 	name = "add prosthetic"
@@ -94,4 +110,3 @@
 			var/obj/item/melee/arm_blade/new_arm = new(target,TRUE,TRUE)
 			target_zone == BODY_ZONE_R_ARM ? target.put_in_r_hand(new_arm) : target.put_in_l_hand(new_arm)
 			return 1
-